Download the structure for interactive viewing

Go to NaCl Rock Salt (Halite) at Stephen Heyes' website at Oxford University and click on the image of the halite crystal structure to download and open in CrystalMaker for viewing, or...

Go to the Extended Structures Libraries on the CrystalMaker website, and download the "Additional Phases" archive. Within the resulting folder "Appendix", click on the file named "NaCl, Halite (B1,Fm3m)" which will open automatically in CrystalMaker, or...

Download the halite structure as halite unit cell( 2kB Jun8 07). This is a cmdf file which you can view with CrystalMaker.

Rotate so you are looking down the main diagonal fo the cube. (From corner to opposite corner.) What is the symmetry in this direction? (ignore rotoinversion for now and just treat as a simple rotation)

This structure contains 2-fold, 4-fold and 3-fold rotation axes. How many identical 2-fold axes are there? How many identical 4-fold axes are there? (Warning: counting these rotational axes is quite difficult for the computer visualization)

How many sets of mirror planes occur in this structure, and what is the angular relation between these planes?